Once more about „round” vowels
Round, in other words, natural vowels are for each mix teacher of the huge importance. Even a very little change in the pronunciation provokes discomfort and enormous change in the reception. If the singer does not correct his/her pronunciation consequently loses the mix. As teachers we should pay special attention to each wider vowel and correct it immediately. In that way we are creating a good habit of the singer so she/he will be able to correct himself/herself while working at home. The fantastic solution is also putting the song to a higher key. The higher we are the better our pronunciation should be because the higher notes require optimal technique. So we often observe the singer’s auto-correction of the vowels during singing in the higher key. The higher we are the narrower the vowel is. That was one of the main concern of the Old Schooling. “It must be remembered, and remembered always, that the modification of all vowels from their pure, as spoken sounds, is absolutely necessary from the physiological and acoustical standpoints. First of all the modification imparts to the vowel a certain rotundity, making the tone more agreeable, and secondly – which is of paramount importance – this rounding of the pharynx to create the rounded vowel has the effect of causing the gradual shortening of the cords as actuated by the appropriate bunch of muscles within the larynx. This is one of the paramount laws of nature which so many would-be teachers seem to ignore to their loss and also their pupils.” (Edgar Herbert-Caesari, Vocal Truth Some of the Things I Teach, republished Travis & Emery 2007, pp.13-14)